The subject matter disclosed herein relates generally to platelet therapy used in various medical applications, such as treatments for surgery or trauma. Certain embodiments relate to platelet activation and control of clotting by varying various activation conditions including, but not limited to, presence and characteristics of a pulsed electric field and calcium presence and concentration.
Use of platelet gel (also called “activated platelet rich plasma”) is an emerging therapeutic approach that may be employed in clinic or other health care facility for a variety of applications, including promoting wound healing (such as after surgery) and hemostasis. In particular, interest in the use of platelet therapy as a wound healing treatment exists for many types of injuries and conditions, such as nerve injuries, tendinitis, osteoarthritis, cardiac muscle injury, and bone repair and regeneration. In addition, the derivation of the platelet gel used on a patient may be autologous, meaning that the platelets are derived from the patient's own tissues and/or fluids. Thus a blood sample, from the patient may be used to derive the platelet gel used to treat the patient.
By way of example, a doctor may draw blood from a patient. The blood may then be centrifuged to generate platelet rich plasma (PRP). Upon platelet activation, the platelets within the blood release growth factor and proteins that facilitate and promote the wound healing cascade. The clinical workflow may, therefore, involve drawing blood from the patient, centrifuging the blood to separate out the platelets, and performing an ex vivo platelet activation, such as using bovine thrombin. The activated platelets or platelet gel may then be applied to the wound or other treatment region. In instances where in vivo platelet activation is instead employed, the doctor may apply the PRP to the site without adding a platelet activator. Platelet activation, which includes growth factor release and clotting, is usually induced by the collagen within connective tissue.
For such ex vivo applications, where thrombin (e.g. bovine thrombin) is used to induce platelet activation, the resulting growth factor levels may be fixed based on the biologic response. That is the amounts and/or respective ratios or proportions of different growth factors are dictated by the nature of the thrombin-based activation. In such reactions, therefore, the clinician is unable to adjust or manipulate the respective amounts or proportions of different growth factors, and must instead make do with the conventional activation compositions. Further, in certain clinical scenarios, it may be desirable to have or not have clotting and/or, in the presence of clotting, to control for the mechanical strength or other characteristics of the clot.